Definitions
American Heritage Dictionary: ro·bot (rbt, -bt) n.
1: A mechanical device that sometimes resembles a human being and is capable of performing a variety of often complex human tasks on command or by being programmed in advance.
2: A machine or device that operates automatically or by remote control.
3: A person who works mechanically without original thought, especially one who responds automatically to the commands of others.
Websters:
1 a : a machine that looks like a human being and performs various complex acts (as walking or talking) of a human being; also : a similar but fictional machine whose lack of capacity for human emotions is often emphasized b : an efficient insensitive person who functions automatically
2 : a device that automatically performs complicated often repetitive tasks
3 : a mechanism guided by automatic controls
RIA defines a robot as: "A programmable multi-function manipulator designed to move material, parts, or specialized devices through variable programmed motion for the performance of a variety of tasks" (RIA)
McKerrow, in 1986 used "A robot is a machine which can be programmed to do a variety of tasks in the same way a computer is an electronic circuit which can be programmed to do a variety of tasks”